Rapid Review: Study on degradation of water soluble film

I am in agreement with these summary comments. The paper is of marginal quality and the results/conclusions were not scientifically sound and should not be taken seriously.

No conflicts for me. 

The laundry list of deficiencies (many of which overlap between the experts) demonstrates the low reliability of the work. I agree that the weight of the comments is much more important than the numbering system. 

Yes, we all agree on the severity of the weaknesses of the experimental approach, and the over-interpretation of the data. 

I am glad to see real consensus around this paper. The comments by experts 1 and 3 really hit the nail on the head, that all 5 reviewers have converged on very similar opinions for most/all aspects of the paper. I am also pleased to notice that everyone agrees that microplastics are indeed concerning and are certainly worth further study, especially considering the massive scale of the quantity of plastics (expert 2), and in particular PVA and PVA variants, that ends up in wastewater. We all agree that the questions initially posed by the authors of the manuscript are good questions. 

None for me.

Again, great alignment between reviewers is encouraging to see (e.g., consensus on the lack of statistical analysis, lack of controls, absence of detail for experimental procedure). Expert 5's comment on the reliability of the FTIR band heights when calculating the ratios. The thickness of the pod PVAlc films would have been nice to know, too.

I also am encouraged of the alignment between experts regarding the weaknesses.

I find that there is consensus among our panel that the potential production of microplastics from detergent pods is worth investigating, especially conditions that may favor microplastic formation. But proper context should be acknowledged. The US EPA considers pods to be safe, hence including PVAlc (which likely has some polyvinyl acetate) within its Safer Choice program. Moreover, the PVAlc component of pods was found to be highly water-soluble and biodegradable in aquatic environments under most conditions encountered under washing conditions, which deters the formation of micrplastics, which are water-insoluble. The US FDA has approved PVAlc for use in food packaging, dietary supplements, and pharmaceutical products.  My take is that because of the heavy use of pods, a lot  of PVAlc winds up in wastewater treatment plants (WWTPs; 10,500 metric tons per year per a 2021 study (DOI: 10.3390/ijerph18116027 ) and we must find out the conditions that are amendable to microplastic formation, especially realizing that WWTPs experience a wide variety of materials and conditions.

I fully agree with Expert 1.
In addition, I believe the differences in scoring result from different backgrounds and whether you usually use the full scale or stay a bit up, even for real poor work.

Good to see that again we all agree. If all comments were combined it becomes clear that this paper has many flaws in the experiments as well as in the interpretation.

Expert 5 is raising an interesting point. While I use these pods as well, I actually have never observed sludge in my washing machine nor the pipes. I also just asked around in a friend group and no one has ever observed this.
Maybe the other experts can also comment on this?

It is very good to see that peer-review works. 5 reviewers (and if SciPinion works experts) come to more or less the same conclusion.
This is obviously not a question to any of the other experts but I am happy to see this.

No additional remarks needed.

Here too there is in general terms consensus amongst the experts and again lots of details are provided to reach the general conclusion of this being a poorly performed study and a poorly written paper. Furthermore, in a numerical sense there is agreement independent of the score being 1 or 4.

There are a multitude of critical comments and observations made by the experts. I tend to agree with the general nature of the comments and observations, but do not think that it is needed to discuss them in detail. This is also inspired by the fact that there are many details that support the overall conclusion of this paper being marginal and very poorly written with conclusions that are not supported by the findings.

In general terms there is agreement on the relevance/importance of the topic of study.

I agree with expert 4 on the FTIR results. My intention was to indicate that from a technical point of view the FTIR measurement were done properly, although indeed no strong conclusions can be drawn from the results.

I agree with the individual reviewers' observations and comments. This is a marginal paper describing experiments that did not directly support the conclusions, even though the scientific question that the authors set out to address seemed to be good and relevant.

Expert 1: I agree with you that the FTIR results proved that the residue contained chemical fingerprints similar to those in the water soluble film. However, these results do not prove that there were microplastics. Microscopes or other imaging techniques are often used to identify microplastics, after which FTIR is  used to determine the type of polymer of the microplastics.